The world’s largest coral reef with an eco-system is the Great Barrier Reef located off the coast of Queensland, Australia. The eco-system is composed of over 2,900 individual reefs, 900 islands stretching for over 1,600 miles over an area of approximately 133,000 sq. mi. More than nearly half the reef has vanished in the last 27 years.

A coral reef ecologist, Katharina Fabricius, from the Australian Institute of Marine Science told LiveScience that she has been diving to the reef since 1988 and has studied the decline. To gather their data, Fabricius and her colleagues surveyed 214 different reefs near the Great Barrier Reef. They studied information from 2,258 surveys to determine the rate of decline between 1985 and 2012. They estimate that the yearly decline is about 3.4 percent of the reef.

There are a few factors causing the decline. The largest factor is wear from the tropical cyclones, crown of thorn starfish that each the coral and boosted from the nutrient run off from agriculture, and coral bleaching from high temperatures; which are rising due to climate change.

How can we save the reef? Some mention that reducing CO2 emissions is key though Fabricius says there is not much that can be done in a short term process. With five category 5 storms that have pounded the reef it has taken a toll on the reef. Efforts are being made to stem the damage of the starfish. The research shows that the reef could rebuild itself in 20-30 years despite the cyclones and bleaching, if the starfish population died back.

Experts feel that it is critical to do something immediately. Over the course of two to three generations the reef can rebuild and sustain its habitat with help.